1. Field of the Invention
The invention relates to a self-propelled construction machine, in particular road milling machine, stabiliser, recycler or surface miner, with a machine frame and an operating drum, wherein the operating drum is positioned in a downwards open drum housing that is closed on both sides by edge protectors adjustable in height. The invention further relates to a method for operating such a construction machine.
2. Description of the Prior Art
The above-mentioned construction machines have a rotating operating drum for processing of ground material, which can be a milling or cutting drum. With the operating drum, for example, damaged pavement layers can be removed, existing road surfaces can be recycled, the land for road construction can be prepared, or mineral resources can be mined.
The operating drum of the known self-propelled construction machines is positioned in a downwards open drum housing, that is closed by a hold-down device positioned in front of the operating drum, when seen in the operating direction, and a stripper positioned behind the drum, when seen in the operating direction. Plates extending in the operating direction, which are referred to as edge protectors, close the drum housing at the sides.
The edge protector of the known self-propelled construction machines is adjustable in height. A mechanism for raising and/or lowering the edge protector is provided for the purpose. The edge protector can be lowered solely under the action of the weight of the edge protector or can be supplemented by additional applied force. In both cases, the edge protector exerts pressure on the ground surface. While doing so, the edge protector stands with its lower edge on the ground surface.
The mechanism for raising and/or lowering the edge protector is actuated by the machine driver, especially when it is necessary to have access to the operating drum. During operation of the construction machine, however, the edge protector is always lowered. Therefore self-propelled construction machines have a circuit which does not permit the edge protector to be fixed in the raised position. Operation of the machine is characterised by a floating mounting of the edge protector, with which the edge protector rests on the ground with a defined contact force.
During operation of the construction machine, in particular on loose substrate, there is the problem that the edge protector becomes entrenched in the ground. From increased traction resistance and hence higher fuel consumption and wear, this can lead to complete stoppage of the machine.